All materials to be ground must be completely dried before grinding. Plant material is dried at 55C and soil is dried at 40C using forced-air ovens. Plant material is ground using either a Wiley Mill, Model 4 or a Wiley Mini Mill. Soil is crushed in a Bico Pulverizer. If a finer grind is required for select tests, a subsample is ground using a mortar and pestle.
